LDR 5mm - Light Dependent Resistor

LDR 5mm - Light Dependent Resistor

A photoresistor or LDR 5mm - Light Dependent Resistor is a resistor whose resistance decreases with increasing incident light intensity; in other words, it exhibits photoconductivity.

A photo-resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron (and its holepartner) conduct electricity, thereby lowering resistance.